baber/WOPTO huggingface dataset:
Patent GB-1277852-A (GB)
Title: Data processing systems
Inventor: WOODRUM LUTHER JAY
IPC: G06F7/24
Filed: 1970-11-13
Abstract: 1277852 Sorting INTERNATIONAL BUSINESS MACHINES CORP 13 Nov 1970 [24 Dec 1969] 54029/70 Heading G4M The sorted sequence of items to be sorted is represented by the sequence of indices associated with their addresses. Variable-length stored records each include a key. The addresses of the records are entered in the unsorted order into an address table, and in each case the index position of the address entry in the table is placed in its correct position in an index table which stores the indices in the sorted order of the corresponding keys as follows. Each new index is placed at the top of the occupied part of the index table (which is filled from the bottom up and the existing entries of which are in the sorted order of the corresponding keys), a binary search being done in the index table to find the proper insertion position for the new index by comparing its corresponding key with those corresponding to the index table entries (keys accessed using the address table, of course). The index table entries above the proper insertion position are moved up to make room and the new index is inserted. When the index table is full, its top entry and the corresponding entry in the address table are removed, and the latter address (or the record) is output as part of the sorted sequence. When end of (unsorted) file is reached, the remaining addresses (or records) are output in the sorted order specified by the index table. A sequential search or a quadratic search may replace the binary search.
Patent GB-1133957-A (GB)
Title: Flame resistant polyurethane compositions and production of ammonium polyphosphates for use therein
IPC: C08K3/32
Filed: 1965-12-21
Abstract: 1,133,957. Ammonium polyphosphates. MONSANTO CO. 21 Dec., 1965 [22 Dec., 1964 (2)], No. 54077/65. Heading C1A. [Also in Division C3] Substantially water - insoluble crystalline ammonium polyphosphates of the general formula H n-m+   2 (NH 4 ) m P n O 3n+1  wherein n is an integer with an average value greater than 10, the maximum value of m is m n + 2 and - is between 0.7 and 1À1, are produced n by thermally condensing (e.g. at 100-350‹ C.) a composition comprising a phosphate containing material together with an ammoniating and condensing agent, or with a combined ammoniating and condensing agent, in the presence as additive of at least 1 part per 10 parts by weight of the composition of a crystalline ammonium polyphosphate as defined above. The phosphate containing material is preferably present in amounts to yield at least 1 mole of ammonia per mole of phosphorous. As phosphate containing materials there are detailed those materials containing or yielding on hydrolysis at least one PO<SP>3</SP> 4 -group, e.g. monoammonium orthophosphate, diammonium orthophosphate, tri - ammonium orthophosphate, orthophosphoric acid, condensed phosphoric acid, phosphorous pentoxide, phosphorous oxyhalides and mixtures of the above. Ammoniating agents detailed are those which supply or release ammonia under the conditions of the thermal condensation reaction, e.g. gaseous ammonia, liquid ammonia, inorganic ammonium salts containing non-oxidizing anions (e.g. halides, carbonates and sulphides) and including ammonium hydroxide, hydroxylamine chloride and fluoride, mono-, di-, and tri-ammonium orthophosphates, ammonium pyrophosphates, urea phosphate, and mixtures of the above. Condensing agents detailed are those which remove water from the system during thermal condensation, e.g. P 2 0 5 , phosphorous oxyhalides, urea phosphates, phosphorous pentahalides and mixtures of the above. Combined ammoniating and condensing agents detailed are nitrogenous compounds capable of releasing ammoniacal nitrogen and condensing with the phosphorous containing materials, e.g. compounds containing one or more amide groups, particularly primary amides and containing the elements carbon and/or sulphur, nitrogen, oxygen and hydrogen as well as no Carbon-carbon bonds. Urea, ammonium carbamate, biuret, sulphamide, sulphamic acid, ammonium sulphamate, guanyl urea, methyl urea, formamide, amino urea, 1-3-di-amino urea and biurea are listed. The ammonium polyphosphates may be incorporated into a composition for making a flame resistant polyurethane composition.
Patent GB-1222201-A (GB)
Title: Improvements in or relating to laundry, textile and other presses
Inventor: GUDGEON RONALD PERCY
IPC: D06F71/06
Filed: 1966-12-02
Abstract: 1,222,201. Laundry presses. R. P. GUDGEON. 1 March, 1968 [2 Dec., 1966], No. 54083/66. Heading D1A. A laundry or like press comprises members 1, 4 which during pressing remain at the same distance apart and between which is provided a bag 2 inflatable by hydraulic or pneumatic pressure to press an article placed between the bag and at least one of the opposed members. As shown, Fig. 3, two members 1, 1a each with a bag 5, 5a are provided carried on a pivoted frame so that either may be brought beneath a single heated member 4. In another arrangement, Fig. 4 (not shown), the bag 5 may be inserted in a garment which is then pressed against both members 1, 4 one or both of which may be heated.
Patent GB-1153917-A (GB)
Title: Preparation of Caesium Metal
Inventor: VANISCOTTE CHRISTIAN
IPC: C22B26/10
Filed: 1967-11-29
Abstract: 1,153,917. Production of caesium. HOUILLERES DU BASSIN DU NORD ET DU PASDE-CALAIS. Nov.29, 1967 [Dec.2, 1966], No.54353/67. Heading C7D. Caesium is produced by reducing a caesium oxide containing mineral, such as "pollucite", containing at least 10% Cs expressed as the oxide, with a stoichiometric excess of silicon at a temperature of at least 1200‹ C. (e.g. 1300-1400‹C.) in the presence of at least 2 moles of lime per mole of silica (initially present and produced during the reaction) in an inert atmosphere (e.g. a flowing atmosphere of N 2  or Ar). The stoichiometric amount of Si is calculated to reduce all the alkali metal oxides and any water which may be present and the excess which is added over this amount is preferably up to 50%. The Cs vapour may be fractionally condensed (e.g. to give a metal with at least 98% purity).
Patent GB-1376614-A (GB)
Title: White pigments suitable for use in paints
IPC: C09C1/00
Filed: 1971-11-23
Abstract: 1376614 Phosphate pigments MIZUSAWA KAGAKU KOGYO KK 23 Nov 1971 54452/71 Heading C1A [Also in Divisions C3 and C4] The invention comprises a white phosphatic pigment of which from 0À1 to 24% by weight is water-soluble (determined by a prescribed method) and which comprises particles wherein the essential constituents are represented by the empirical formula M<SP>1</SP>O 2 .xY 0 (0À1 to 1À5+ mx<SP>1</SP>/ 2 ).P 2 O 5  wherein M<SP>1</SP> represents silicon, titanium or zirconium, x and x<SP>1</SP> are 0 when M<SP>1</SP> represents titanium or zirconium but are 0 or a positive number of up to 6 when M<SP>1</SP> represents silicon, Y represents NH 3  or M<SP>2</SP>On/ 2 , wherein M<SP>2</SP> represents an alkali metal, an alkaline earth metal, aluminium, lead or zinc and n is the valence of M<SP>2</SP>, and m is 1 when Y is NH 3  but is n when Y is M<SP>2</SP>On/ 2 , the particles having a rate of aggregation (as defined) below 50% and a particle size below 20 microns. Zirconium phosphate is prepared by reacting ZrNO 3  with H 3 PO 4  in various mole ratios, followed by calcination at 150-900‹ C. (Examples 3 and 4). Other Zr sources mentioned are (a) dissolving the alkali fusion product of zircon or baddeleyite in H 2 SO 4 , HCl, or HNO 3 , (b) passing Cl 2  through Zr mineral and coke to give ZrCl 4 , and (c) hydrolysing a Zr solution to precipitate hydroxide.  Silicon phosphate and complex silicon metal phosphates are prepared by reaction of (a) a source of SiO 2 , e.g. precipitated SiO 2  gel (Example 1), H 2 SO 4 -treated montmorillonite or slag, or roasted SiO 2  gel (Example 6), Al, Ca, Mg or Na silicate, kaolin, montmorillonite, zeolite, or diatomaceous earth (Example 7), with (b) a source of P 2 O 5 , e.g. H 3 PO 4  (Example 1), P 2 O 5 , HPO 3 , H 4 P 2 O 7 , H 3 PO 3 , H 2 PO 2 , (NH 4 ) 2 HPO 4 , Na 2 HPO 4 , Na 4 P 2 O 7 , (NaPO 3 ) 6 , NaPO 3 , Na 5 P 3 O 10 , KH 2 PO 4 , Ca 3 (PO 4 ) 2 , AlPO 4 , Zn 3 (PO 4 ) 2 , Na 2 HPO 3 , or NaH 2 PO 2  (Example 8), in various Si/P mole ratios (see Example 4), followed by calcination at 150-1000‹ C. A chloride, bromide or iodide of Li, Na, K, Mg, Ca, Ba, Zn, Al or Zn may be added. Ammoniated silicon phosphate is prepared by similar methods, incorporating NH 3 , NH 4  phosphates, urea, ammonium carbamate, guanylurea, aminourea, or biurea. In Example 9, NH 4 OH is absorbed on SiO 2  gel and H 3 PO 4  added. Titanium phosphate is prepared by reacting TiCl 4  with H 3 PO 4  in various mole ratios followed by calcination at 110-800‹ C. The products (Examples 2 and 4) may be ball milled in an organic solvent, preferably methanol, but others are listed. The solvent may contain a dissolved coating agent, e.g. resins, stearic acid, or Ca or Ba stearate.
Patent GB-1249533-A (GB)
Title: Improvements in or relating to thread guides
IPC: B65H57/14
Filed: 1969-11-10
Abstract: 1,249,533. Winding thread. LEMA-LEZZENI MARIO S.p.A. 10 Nov., 1969 [12 Nov., 1968], No. 54862/69. Headings DID and D1J. A thread laying on device for a winding machine comprises an eccentrically mounted pulley 10 mounted on a member 11 which is carried by the reciprocating traverse frame of the machine. Thus the thread running to the package is oscillated along the package axis and the thread is laid with an undulating pattern. Member 11 is adjustably mounted on the reciprocating frame and the axle 22 of pulley 10 is adjustably mounted in a support block 21 which is itself vertically adjustable by a screw 17.
Patent GB-1068490-A (GB)
Title: Improvements in or relating to supercharged internal combustion engines
Inventor: RUFFLES PHILIP CHARLES
IPC: F02B33/42
Filed: 1965-12-24
Abstract: 1,068,490. Charging engines; pressure exchangers; motor power plant. ROLLS-ROYCE Ltd. Dec. 24, 1965, No. 54890/65. Headings F1B; F1N and F1Q. The exhaust gases from either a rotary or (as shown) a reciprocating I.C. engine are led via a duct 16 to a pressure exchanger 10, which they enter and leave via ports 13b and 14b respectively, and via a duct 18 to a turbine 19 mounted on the engine main shaft 3. In modifications the exhaust gases may flow to the turbine first and then on to the pressure exchanger, or the exhaust gases may be divided into two streams feeding the turbine and pressure exchanger respectively. The turbine may be mounted on another shaft which may drive the engine mainshaft through gearing. The pressure exchanger 10 comprises a rotor driven by shaft 3 and formed with a number of Cells 10, which are open at both ends, fixed plates at either end of the rotor being formed with ports 13a, 13b, 13c and 13d. As they reach port 13b, air in each cell is compressed by the exhaust gases and subsequently discharged through port 14a and duct 17 to the engine. High pressure exhaust gases are discharged when each cell reaches the port 14b and subsequently fresh air is inducted through port 13a. If the turbine is mounted on another shaft, then this may be used to drive the pressure exchanger rotor, or alternatively the rotor may be driven merely by the passage of gas therethrough.
Patent GB-1371974-A (GB)
Title: Tape drive mechanism in recording and or reproducing apparatus
IPC: G11B15/29
Filed: 1972-11-28
Abstract: 1371974 Feeding record tapes MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 28 Nov 1972 [1 Dec 1971] 55006/72 Heading G5R A pinch roller 1, Figs. 1 and 3, or 57, Fig. 7, rotatably mounted on a pivoted arm 2 or 56 is biased away from a capstan 14 or 59, e.g. by a spring 5 or 60, and is moved towards the capstan in consequence of the movement of a reciprocable actuating member 13 or 53 which has a surface engaging a confronting surface on the pinch roller arm 2 or 53, at least one of the engaging surfaces being a curved projection, e.g. a roller. As shown, the driving means for the actuating member is a solenoid 8. The actuating member 13 may be telescopically constructed so as to be adjustable in length by means of a tool (42), Fig. 5 (not shown), carrying a pinion (40) engageable with a rack (36), Fig. 4 (not shown), on one component of the actuating member 13.
Patent GB-1368817-A (GB)
Title: Mineral mining equipment
IPC: E21C35/20
Filed: 1972-10-31
Abstract: 1368817 Endless conveyers in mines COAL INDUSTRY (PATENTS) Ltd 31 Oct 1972 [26 Nov 1971] 55058/71 Heading B8A [Also in Division E1] An endless conveyer for use on a long wall coal face 1 comprises upper and lower rungs 2, 3, a driven endless chain carrying scraper bars 10 at least some of which are provided with ploughing or planing tools 13, and conveyer carrying assemblies 4 which allow both simultaneous vertical adjustment of both runs and relative vertical adjustment between the runs. Each assembly 4 comprises: a lower beam 20 having ground engaging feet 21, 22, an upper beam 23 pivoted at 27 to the lower beam and supporting the lower run of the conveyer, an hydraulic jack 50 acting between the beams, and an hydraulic ram 31 also mounted on the upper beam and carrying the upper run. A screw arrangement (53, Fig. 4, not shown) interconnects the beams 20, 23 to provide an adjustable extension control for jack 50. The bars 10 are guided by a series of alternate relatively short 11, relatively long 12, pans and the assemblies 4 connect at the ends of pans 12.
Patent GB-1209745-A (GB)
Title: Improvements in conveyor systems
IPC: A24C5/352
Filed: 1966-12-12
Abstract: 1,209,745. Endless conveyers. MOLINS MACHINE CO. Ltd., D. W. MOLINS, and T. ROWLANDS. 11 Dec., 1967 [12 Dec., 1966], No. 55561/66. Heading B8A. In an overhead endless conveyer 4 conveying trays of cigarettes in a forward path from manufacturing machines to packing machines and conveying empty trays in a return path from the packing machines to the manufacturing machines, the forward and return paths are linked by a pair of endless conveyer belts 6, 7 to even out fluctuations in the packing and manufacturing machines. Each belt 6, 7 is with loading and unloading means (not shown) whereby to respectively transfer empty trays on the forward path to the return path and so bypass the packing machines and to transfer loaded trays from the return path to the forward path and so by-pass the manufacturing machines. The conveyers 6, 7 which serve as temporary storage for the trays, are arranged so that when the conveyer 4 feeds a tray to one of the conveyers 6, it receives a tray of the opposite conditions from the other conveyer. The buildup of trays on one or other of the conveyers 6, 7 may be used to control the packing and manufacturing machines.
Patent GB-900950-A (GB)
Title: New water-soluble dyestuffs containing methylol groups and dyeings obtainable with these dyestuffs
Inventor: WAECHTER RUDOLF
IPC: D06P1/382
Filed: 1959-10-23
Abstract: 2 - (21 - hydroxybenzylidene - amino)-4:6-diamino-1:3:5-triazine is prepared by reacting salicyl aldehyde with melamine in N-methylpyrrolidone.  2 - (41 - aminophenylsulphonylamino)-4:6-diamino-1:3:5-triazine is prepared by reacting melamine with 4 - nitrobenzene - sulphonyl chloride and reduction of the nitro group.ALSO:The invention comprises water-soluble dyes of formula [D]-(CH2OH)n wherein D is the residue of an azo or anthraquinone dyestuff containing at least one water-solubilising group and containing at least one 2 : 4-diamino-1 : 3 : 5-triazine group in the molecule and in which hydrogen atoms susceptible to reaction with formaldehyde have been replaced by methylol groups and n is 1 to 8.  They are prepared by reacting a suitable dye or intermediate with formaldehyde or an agent giving formaldehyde such as paraformaldehyde, formaldehyde diethylacetyl or N-methylolurea in a medium of pH 6 to 11 and if necessary converting the intermediate to an azo or anthraquinone dye.  The dyes give yellow and red shades on cellulose, polyamide and polyurethane fibres preferably in the presence of acids or acid salts and the dyed goods may be heated.  In Examples: (1) the dye 1-aminobenzene-2-sulphonic acid --> 2-(21-hydroxybenzylidene-amino)- 4:6-diamino- 1 : 3 : 5-triazine is treated with formaldehyde or the coupling component is methylolated and treated with the diazo compound; (2) 2-(41-aminophenylsulphonylamino)- 4 : 6- diamino1 : 3 : 5-triazine is diazotised and coupled with 1-naphthol-3 : 5-disulphonic acid and the dyestuff treated with formaldehyde; a number of alternative coupling components are specified: (3) 1-amino-4-bromoanthraquinone-2-sulphonic acid is reacted with 2-(41-aminobenzenesulphonylamino)- 4 : 6-diamino-1 : 3 : 5-triazine and the product reacted with formaldehyde; (4) the dye 2-aminonaphthalene-6 : 8-disulphonic acid --> 2-(41-hydroxyphenylamino)-4 : 6-diamino-1 : 3 : 5-triazine is treated as in (1).
Patent GB-1381618-A (GB)
Title: Anthraquinone dyes and their production
IPC: C07D295/20
Filed: 1972-12-05
Abstract: 1381618 Anthraquinone dyes GAF CORP 5 Dec 1972 [20 Dec 1971] 56142/72 Heading C4P The invention comprises dyestuffs of the general formula wherein A is a mono-, bi- or tri-cyclic aryl radical, B is halogen lower alkyl (i.e. lower is C 1 -C 5 ), lower alkylmercapto, amino, lower alkylamino, di-lower alkylamino or phenylamino, n is 0-4, R 1 , R 2 , R 3  and R 4  are H, lower alkyl, C 3 -C 6  cycloalkyl or phenyl, or R 3  and R 4  together with the linked nitrogen atom and optionally a further nitrogen or oxygen atom may form a 5- or 6-membered heterocyclic ring, e.g. pyrrolidino, piperidino, piperazino or morpholino, X is H or SO 3 H and m is 1-4. The compounds where X is SO 3 H are prepared by reacting a 1,5-diamino-4,8-dihydroxy-anthraquinone-3,7-disulphonic acid with an aryloxy alkoxy carbamate of the general formula wherein A, B, n, m, R 3  and R 4  are as defined above in concentrated sulphuric acid containing boric acid, drowned in aqueous alkali to pH 8À5-9À5 and then heated under reflux, filtered and water washed. Desulphonation to give compounds where X=H is effected using sodium hydrosulphite. The dyes give blue shades on polyester, polyamide, e.g. nylon, polyolefins, di- or tri-acetates and wool.
Patent GB-1181801-A (GB)
Title: Carrier Device for Moving Containers
Inventor: WHEELER KENNETH JOHN
IPC: B66C19/00
Filed: 1966-05-27
Abstract: 1,181,801. Straddle trucks; container traffic; jacks. ALEXANDER STEPHEN & SONS Ltd. 16 May, 1967 [27 May, 1966; 19 Dec., 1966], Nos. 23820/66 and 56640/66. Headings B8E, B8H and B8J. [Also in Division Fl] A trailer for lifting and transporting load containers comprises a U-shaped base frame, each arm 1 of which supports a pair of hydraulic rams 11-14 in structures 15 for raising a lift frame 22. The lift frame comprises a frame 23 which is provided with twist lock connections 24, for engagement with connections on the upper corners of the container 10, and with legs 25 which engage fixed guides 16 on the structures 15. The frame 22 is lifted by chains 20 secured to the bottom of the legs 25 and to the structures 15 and passing over pulleys 19 on the ram piston-rods. The rams 11-14 are controlled to compensate for out of balance loading of the container, the rams 11, 13, 14 moving in correspondence with ram 12. Servo-control valves 28-30 are each operated by a pivoted lever 32 connected between the valve spool and a sprocket 34 arranged between a pair of roller chains 35. The chains 35 are connected at one end to cables 36 passing around pulleys 37 on pneumatic rams 38 and at the other end to cables 39 passing around rollers 40 to the piston-rods 18 of the appropriate hydraulic rams 11-14. Locking valves 47 are provided for locking the rams in their raised positions and are connected by pilot lines 76 to a solenoid-operated valve 48 in parallel, electrically, with the main control valve 31. The twist lock mechanisms are actuated hydraulically under the control of a valve 55.
Patent GB-1400757-A (GB)
Title: Vacuum packing apparatus and methods
IPC: B65B11/52
Filed: 1972-12-11
Abstract: 1400757 Attaching articles to cards GMT SA 11 Dec 1972 [9 Dec 1971] 57042/72 Heading B8C A plurality of products 17 are placed on a permeable sheet 11 which is transferred to a position where a plastics film 32 is heated and softened and where vacuum is applied through the sheet 11 in order to draw the film around the products and allow it to adhere to the sheet. The articles 17 are placed on the sheet 11, which is of cardboard, between meshes of a grid 9 resting on a carriage 7, the sheet and the grid then being moved manually by means of the carriage 7, on which they rest, to a position above a plate 18 which is then lowered to a position A 2  whereby to remove the article-carrying sheet from the carriage and allow the insertion of another sheet as the carriage is returned to its original position. The plastics film 32, from a roll 33, is drawn over a frame 26 beneath a heating unit 31 and the article-carrying sheet 11 is raised to a position A 3  within the frame 26 in which it is clamped by a frame 27. A vacuum source is then applied to a cavity (23) in the plate (18), Fig. 4 (not shown), to thereby draw the plastics sheet over the articles and on to the sheet 11. After cooling, the frame 27 is raised and the sealed length of sheet 11 is withdrawn in the direction f 3 . A table 43, Fig. 9, adjacent the outlet side of the machine includes a support for cutter blades 45 and drums 48 by means of which the sealed article-carrying sheet 11 is cut into strips which are subsequently cut by means (not shown) transversely between each packaged article. The sheets 11 may be fed to the machine by a rotary table. The heater unit comprises a pair of piston-operated cases 34, 35 which are operated to cover or expose heating elements (42), Fig. 7 (not shown). Also vertical movement of the plate 18 is controlled by rams 20, 21.
Patent GB-1252263-A (GB)
IPC: A61K/
Filed: 1968-12-02
Abstract: 1,252,263. 1 α,2α-Methylene-4-chloro-7-methyl-steroids. SCHERING A.G. 2 Dec., 1968 [7 Dec., 1967], No. 57075/68. Heading C2U. Novel steroids of the formula (wherein Y is C(α-R 2 )(#-OR 1 ), C(α-R 3 )(#-COCH 3 ) or C(α-R 3 ) (#-COCH 2 OR 1 ) or is a bismethylenedioxy dihydroxyacetone side chain, R 1  being H or acyl, R 2  being H or a C 1-5  aliphatic hydrocarbon radical and R 3  being H, OH or O acyl or other functional OH derivative; Z is H 2 , H (α- or #-OH) or O ; and the #<SP>6</SP> double bond is optional) are prepared by reacting the corresponding 6#,7#-methylene steroids not containing an 11-OH group with a hydrohalic acid HX (X is Cl, Br or I) to form a 7#-CH 2 X substituted steroid and reducing this. In the products an esterified OH may be saponified, a bis-methylenedioxy side chain protective group split off, and/or a free OH group esterified, and/ or a double bond introduced into the 6,7-position, possibly via a 6-halo intermediate, and/or an 11-keto group reduced, if desired with intermediate protection of the 3-keto group and a 20-keto group. 1α,2α - Methylene - 6#,7# - methylene steroids used as starting materials are prepared from 1,4, 6-trienes via bis-pyrazolines. 4 -Chloro.17, 20 ; 20,21 - bismethylenedioxy - 1,4,6 - pregnatriene- 3,11-dione is prepared by chlorination of the 4- unsubstituted compound. The novel steroids of the androstane series have a strong inhibiting action on the hypophysis and are suitable for the treatment of climacteric complaints; while those of the pregnane series have strong gestagenic activity and may be used as contraceptives. The novel steroids are made up into pharmaceutical preparations with suitable carriers.
Patent GB-1420744-A (GB)
Title: Liquid discharge nozzles
IPC: B04B11/00
Filed: 1971-12-09
Abstract: 1420744 Liquid distribution nozzle DEFENCE SECRETARY OF STATE FOR 9 March 1973 [9 Dec 1971] 57254/71 Heading B2F An elongated nozzle 10 for depositing a liquid suspension evenly across the inner surface of a filter drum, is connected to a feed chamber 9 by a converging passage 11. The chamber 9 has a right angled inlet 4, 8 and an upper guide surface 16 which reduces the section to maintain flow velocity; the first part of the surface 16 is shaped to cause deflection of the incoming material towards the nozzle outlet. Baffles 14 in the passage 11 have rounded upper edges.